Production of percarbonates.



STATES PATENT OFFICE.

' mnnxnncm, or FRANKFORT-ON-THE-MAIN, GERMANY. rnonucrrou or PERCABIBONATES.

1,263,258 Specification of Letters Patent. Patented A P 16, 1918, F0 Drawing. Application filed .tuuary 3, 1918. Seria11qo.210 .215. To all whom it may concern: quantities of salt as I am using did not in- Be it known that I, O'rro LmBKNncHT, a terfere with the process itselffnor did the subject of the German Emperor, and resisalt unfavorably influence the hydrogen dent of Frankfort-omthe-Main, Germany, peroxid employed. Likewise did the salt have invented certain new and useful Imcontents of the solution in no way influence provements in the Production of Percarthe durability of the solid percarbonate obonates, of which the following is a specifitained in accordance with mynovel method. cation. When proceeding according to my present My present invention relates to the proinvention, one may start either with a di- 6 duction of percarbonates, and has for its luted solution of hydrogen peroxid or with percarbonate bydissol inf a corresponding common salt or the 11 object to provide a novel process of obtaina concentrated solution of hydrogeh peltin alkali-metal percarbonates from aqueous oxid; in any case the yield is considerably so utions. increased by an addition of somewhat simi- It has been proposed to produce sodium lar quantities ('2'. e. a l rge proportion) of die separating subproportion of soda in a uted solution of stances. I prefer to work with a solution of' hydrogen peroxid containing approximately a limited water content, which feature I 3 per cent. of hydrogen percxid, and adding, have described and claimed in another ap after some lapse of time, larger quantities of plication. 7t alcohol, for instance, a. quantity approxi- I have given some examples to render my mately equal to three times the volume of invention more clear; however,I desire it to v the hydrogen peroxid solution, and thereby be understood that my invention is not lim recipitating the percarbonate formed. ited to the examples and the data given-Q ow, I have discovered that instead of the ihereimbut is applicable in an case where expensive ethyl alcohol, I may advanta- It is desired to separate percar onates from geously use separating salts, that is salts havan aqueous solution. mg a tendency to induce a separation of the I have further discovered that it is very percarbonate from the solution, for instance, advantageous to conduct the process in the readily dissolving salts, such as common presence of protective substances such, for salt, sodium nitrate, and others for the instance, as sodium silicate, or magnesium separation of the percarbonate. Especially silicate, the yield of percanbonate from a the cheap common salt has been found to given quantity of peroxid being thereby inproduce excellent results. The Separating creased. and the percarbonate rendered more salts may already be resent in the hydrogen stable. 7 peroxid solution wit which the process is What I claim as my invention, and desire started, or the separating salts ma .be added to secure by Letters Patent of the United during the formation of ercar onate; or States of America, is

. the separating salts may e added to the 1. A process of obtainin pcrcarbonates solution after the completion of the process from aqueous solutions w ich comp ises of formin percarbonates. adding to a dilute aqueous solution of a er- If to a ydro n peroxid solution of 10 l'car nate a salt having a tendency to in a per cent. so mucfi of calcined soda is added a separation of the percarbonate from the that for each one half gram of molecular solution. hydrogen peroxid there is resent one gram 2. A process of obtaining alkali-meta] of mo ecular soda, the yiel of solidpercarpercarbonates from a ueous solutionmwhjch bonate obtained after cooling, filtering, and comfig-ises addingtoa' ilute aqueous solution drying, will amount but to about 60 per cent. of a alimetal percarbonate a large proporof the hydrogen eroxid employed. Upon tion of a salt having a tendency to induces adding to the hyd i'ogen peroxid so much of Separation of the percarbonate from the so- 106 common salt that a salt solution of 10 per lution. Q cent. results, the yield will amount to up- 3. A rocess twbtaining sodium peroarward of 80'per cent; and if a salt solution bonate in aq eous solutions which com oi 20 or cent. is produced the yield of solid prises adding to a dilute aqueous solution. percar onate will amount to almost 90 r of sodium percarbonate a large proportion (in cent. I observed the surprising fact t at of common salt. l the presence of such comparatively large 4. A process of producing alkalrmetal.

percarbonates which comprises adding to a dilute solution of hydrogen peroxid, containing an alkali-metal carbonate, a salt having a tendency to induce a'separation of the resulting percarbonate from the solution. A

5. A process of producin sodium percarbonate which comprises a ding to a dilute solution of hydrogen peroxid containing sodium carbonate a large proportion of common salt.

6. A recess of obtaining pemaflaonatcs from di ute aqueous solutions which comrises inducin a separation of the percaruonate from t e dilute aqueous solution by means of a percarbonate-separating salt in the presence of a protective substance.

7 A process of obtaining sodium percarbonate from dilute aqueous solutions which comprises separating the sodium percarbonate from the dilute aqueous solutlon in the presence of common salt and a protective substance.

8. A process of obtainin alkali-metal percarbonates from aqueous so utionswhich comprises inducing the separation of the alkalimetal percarbonate from the aqueous solution in the presence of common salt 561110- what similar in quantity to the amount of percarbonate present, and in the presence of a protective substance.

9. A process of producing alkali-metal percarbonates which comprises inducing the separation of alkali-metal percarbonate from adilute solution of hydrogen peroxid containing an alkali-metal carbonate in the presence of a percarbonate-separating salt and a roteotive substance.

10. process of producing sodium percarbonate which comprises inducing the separation of sodium percarbonabe from a solution of hydrogen peroxid containing sodium carbonate in the presence of a protective substance by means of a quantity of common salt somewhat similar to the amount of percarbonate formed.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

OTTO LIEBKNECHT.

Witnesses WILHELM S'lii'rznn, ALMA LAUGK. 

